scholarly journals Mycobacterium tuberculosisProtein Rv3841 Activates Dendritic Cells and Contributes to a T Helper 1 Immune Response

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Seunga Choi ◽  
Han-Gyu Choi ◽  
Ki-Won Shin ◽  
Yong Woo Back ◽  
Hye-Soo Park ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Dendritic Cells ◽  
Protective Efficacy ◽  
Mitogen Activated Protein Kinase ◽  
T Helper ◽  
T Helper 1 ◽  
Cell Immunity ◽  
Mitogen Activated Protein ◽  
Mycobacterial Growth

The attenuated vaccineMycobacterium bovisBCG (Bacille Calmette Guerin) has limited protective efficacy against TB. The development of more effective TB vaccines has focused on the mycobacterial antigens that cause strong T helper 1 (Th1) responses. Mtb protein Rv3841 (bacterioferritin B; BfrB) is known to play a crucial role in the growth of Mtb. Nonetheless, it is unclear whether Rv3841 can induce protective immunity against Mtb. Here, we studied the action of Rv3841 in maturation of dendritic cells (DCs) and its engagement in the development of T-cell immunity. We found that Rv3841 functionally activated DCs by upregulating costimulatory molecules and increased secretion of proinflammatory cytokines. Activation of DCs by Rv3841 was mediated by Toll-like receptor 4 (TLR4), followed by triggering of mitogen-activated protein kinase and nuclear factor-κB signaling pathways. In addition, Rv3841-matured DCs effectively proliferated and polarized Th1 immune response of naïve CD4+and CD8+T-cells. Moreover, Rv3841 specifically caused the expansion of CD4+CD44highCD62LlowT-cells from Mtb-infected mice; besides, the T-cells activated by Rv3841-matured DCs inhibited intracellular mycobacterial growth. Our data suggest that Rv3841 induces DC maturation and protective immune responses, a finding that may provide candidate of effective TB vaccines.

scholarly journals The Role of Dendritic Cells in TB and HIV Infection

2020 ◽  
Vol 9 (8) ◽  
pp. 2661
Author(s):  
Rachel Abrahem ◽  
Emerald Chiang ◽  
Joseph Haquang ◽  
Amy Nham ◽  
Yu-Sam Ting ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Dendritic Cells ◽  
Dendritic Cell ◽  
Hiv Infection ◽  
Cell Response ◽  
Defense Mechanism ◽  
Critical Role ◽  
Cytokine Release ◽  
T Helper 1

Dendritic cells are the principal antigen-presenting cells (APCs) in the host defense mechanism. An altered dendritic cell response increases the risk of susceptibility of infections, such as Mycobacterium tuberculosis (M. tb), and the survival of the human immunodeficiency virus (HIV). The altered response of dendritic cells leads to decreased activity of T-helper-1 (Th1), Th2, Regulatory T cells (Tregs), and Th17 cells in tuberculosis (TB) infections due to a diminishment of cytokine release from these APCs, while HIV infection leads to DC maturation, allowing DCs to migrate to lymph nodes and the sub-mucosa where they then transfer HIV to CD4 T cells, although there is controversy around this topic. Increases in the levels of the antioxidant glutathione (GSH) plays a critical role in maintaining dendritic cell redox homeostasis, leading to an adequate immune response with sufficient cytokine release and a subsequent robust immune response. Thus, an understanding of the intricate pathways involved in the dendritic cell response are needed to prevent co-infections and co-morbidities in individuals with TB and HIV.

Immunopotent Polysaccharides of Different Sources Selectively Activate Human Dendritic Cells.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3873-3873
Author(s):  
Godfrey ChiFung Chan ◽  
W.K. Chan ◽  
H.K. Law ◽  
Z.B. Lin ◽  
Y.L. Lau
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
T Helper ◽  
T Helper 1 ◽  
Xtt Assay ◽  
Peripheral Blood Mononuclear ◽  
Human Dendritic Cells

Abstract Background: Purified polysaccharides extracted from plants and fungi have been shown to induce immune responses in-vivo and vitro over the past decade. Currently, most of these polysaccharides are found to be glucan but with different branch structure and sizes. Their relative potency and effect on human immune cells remains unknown. This study aims to compare their relative effect on human dendritic cell, the most potent antigen presenting cell. Materials & Methods: We selected 2 prototypes of purified polysaccharides extracted from: 1) Ganoderma lucidum (GL, Lingzhi, Reishi) mycelium, a widely used herb with long and branching β (1® 3), (1® 6) glucan structure (provided by Prof. Lin ZB, Beijing) and 2) Barley with shorter and different branching β (1® 3), (1® 4) structure (provided by Prof. Cheung VNK, NY). Their characteristics and chemical properties had been reported previously. Human peripheral blood mononuclear cells (PBMCs) proliferation was studied by XTT assay. Human dendritic cells (DCs) were derived from monocytes and maturation of DCs were determined by: a) immunophenotypic shift using flow cytometer; 2) dextran endocytosis assay and 3) mixed lymphocytes reaction. Cytokine secretions were determined by ELISA test. Comparisons between means were by nonparametric Student’s t test (2-tailed). Results: We found that purified polysaccharides from GL but not barley could induce PBMCs proliferation and maturation of DCs. GL polysaccharides could enhance phenotypic and functional maturation of DCs with significant IL-12 and IL-10 production. DCs were relatively inert to Barley glucans stimulation. However, both polysaccharides did not polarize T cells into the direction of T helper 1, T helper 2 or regulatory T cells. Conclusions: Our study shown that purified polysaccharides extracted from plants and fungi have different effect on human DCs and their potency and effects are probably affected by their respective sources and structures.

scholarly journals Arginine Enhances Induction of T Helper 1 and T Helper 2 Cytokine Synthesis by Peyer’s Patch αβ T Cells and Antigen-Specific Mucosal Immune Response

1998 ◽  
Vol 62 (12) ◽  
pp. 2334-2340 ◽  
Author(s):  
Toshiya KOBAYASHI ◽  
Masafumi YAMAMOTO ◽  
Takachika HIROI ◽  
Jerry MCGHEE ◽  
Yasuyoshi TAKESHITA ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Mucosal Immune Response ◽  
Peyer’S Patch ◽  
T Helper ◽  
Peyer's Patch ◽  
T Helper 1 ◽  
T Helper 2 ◽  
Cytokine Synthesis ◽  
Αβ T Cells

scholarly journals Immunosequencing and epitope mapping reveal substantial preservation of the T cell immune response to Omicron generated by SARS-CoV-2 vaccines

2021 ◽  
Author(s):  
Damon H. May ◽  
Benjamin E. R. Rubin ◽  
Sudeb C. Dalai ◽  
Krishna Patel ◽  
Shahin Shafiani ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Cellular Immune Response ◽  
Epitope Mapping ◽  
Protective Efficacy ◽  
T Cell Response ◽  
Cell Immune Response ◽  
Cell Immunity ◽  
Cellular Immune

The Omicron SARS-CoV-2 variant contains 34 mutations in the spike gene likely impacting protective efficacy from vaccines. We evaluated the potential impact of these mutations on the cellular immune response. Combining epitope mapping to SARS-CoV-2 vaccines that we have determined from past experiments along with T cell receptor (TCR) repertoire sequencing from thousands of vaccinated or naturally infected individuals, we estimate the abrogation of the cellular immune response in Omicron. Although 20% of CD4+ T cell epitopes are potentially affected, the loss of immunity mediated by CD4+ T cells is estimated to be slightly above 30% as some of the affected epitopes are relatively more immunogenic. For CD8+ T cells, we estimate a loss of approximately 20%. These reductions in T cell immunity are substantially larger than observed in other widely distributed variants. Combined with the expected substantial loss of neutralization from antibodies, the overall protection provided by SARS-CoV-2 vaccines could be impacted adversely. From analysis of prior variants, the efficacy of vaccines against symptomatic infection has been largely maintained and is strongly correlated with the T cell response but not as strongly with the neutralizing antibody response. We expect the remaining 70% to 80% of on-target T cells induced by SARS-CoV-2 vaccination to reduce morbidity and mortality from infection with Omicron.

scholarly journals Vaccination with the Recombinant Brucella Outer Membrane Protein 31 or a Derived 27-Amino-Acid Synthetic Peptide Elicits a CD4+ T Helper 1 Response That Protects against Brucella melitensis Infection

2005 ◽  
Vol 73 (12) ◽  
pp. 8079-8088 ◽  
Author(s):  
Juliana Cassataro ◽  
Silvia M. Estein ◽  
Karina A. Pasquevich ◽  
Carlos A. Velikovsky ◽  
Silvia de la Barrera ◽  
...  
Keyword(s):  
T Cells ◽  
Synthetic Peptide ◽  
Cytotoxic T Lymphocyte ◽  
Brucella Melitensis ◽  
Protective Efficacy ◽  
T Helper ◽  
T Helper 1 ◽  
Th1 Response ◽  
Lymphocyte Activity

ABSTRACT The immunogenicity and protective efficacy of the recombinant 31-kDa outer membrane protein from Brucella melitensis (rOmp31), administered with incomplete Freund's adjuvant, were evaluated in mice. Immunization of BALB/c mice with rOmp31 conferred protection against B. ovis and B. melitensis infection. rOmp31 induced a vigorous immunoglobulin G (IgG) response, with higher IgG1 than IgG2 titers. In addition, spleen cells from rOmp31-immunized mice produced interleukin 2 (IL-2) and gamma interferon, but not IL-10 or IL-4, after in vitro stimulation with rOmp31, suggesting the induction of a T helper 1 (Th1) response. Splenocytes from rOmp31-vaccinated animals also induced a specific cytotoxic-T-lymphocyte activity, which led to the in vitro lysis of Brucella-infected macrophages. In vitro T-cell subset depletion indicated that rOmp31 immunization elicited specific CD4+ T cells that secrete IL-2 and gamma interferon, while CD8+ T cells induced cytotoxic-T-lymphocyte activity. In vivo depletion of T-cell subsets showed that the rOmp31-elicited protection against B. melitensis infection is mediated by CD4+ T cells while the contribution of CD8+ T cells may be limited. We then evaluated the immunogenicity and protective efficacy of a known exposed region from Omp31 on the Brucella membrane, a peptide that contains amino acids 48 to 74 of Omp31. Immunization with the synthetic peptide in adjuvant did not elicit a specific humoral response but elicited a Th1 response mediated by CD4+ T cells. The peptide in adjuvant induced levels of protection similar to those induced by rOmp31 against B. melitensis but less protection than was induced by rOmp31 against B. ovis. Our results indicate that rOmp31 could be a useful candidate for the development of subunit vaccines against B. melitensis and B. ovis.

Intranodal injection of semimature monocyte-derived dendritic cells induces T helper type 1 responses to protein neoantigen

Blood ◽  
2003 ◽  
Vol 102 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Michel Gilliet ◽  
Martin Kleinhans ◽  
Erica Lantelme ◽  
Dirk Schadendorf ◽  
Günter Burg ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Cytokine Profile ◽  
Cd4 T Cell ◽  
Delayed Type Hypersensitivity ◽  
T Helper

Abstract Dendritic cells (DCs) represent the most potent antigen-presenting cells of the immune system capable of initiating primary immune responses to neoantigens. Here we characterize the primary CD4 T-cell immune response to protein keyhole limpet hemocyanin (KLH) in 5 metastatic melanoma patients undergoing a tumor peptide–based dendritic cell vaccination trial. Monocyte-derived dendritic cells displaying a semimature phenotype, as defined by surface markers, were loaded ex vivo with antigen and injected intranodally at weekly intervals for 4 weeks. All patients developed a strong and long-lasting delayed-type hypersensitivity reactivity to KLH, which correlated with the induction of KLH-dependent proliferation of CD4 T cells in vitro. Secondary in vitro stimulation with KLH showed significant increase in interferon-γ and interleukin-2 (IL-2) but not IL-4, IL-5, nor IL-10 secretion by bulk T cells. On the single-cell level, most TH1 cells among in vitro–generated KLH-specific T-cell lines confirmed the preferential induction of a KLH-specific type 1 T helper immune response. Furthermore, the induction of KLH-specific antibodies of the IgG2 subtype may reflect the induction of a type 1 cytokine profile in vivo after vaccination. Our results indicate that intranodal vaccination with semimature DCs can prime strong, long-lasting CD4 T-cell responses with a TH1-type cytokine profile in cancer patients. (Blood. 2003;102:36-42)

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